1. Cut the puff pastry into 4 equal parts.
2. Make several vertical cuts in each half without reaching the edges. Brush with melted butter and fold the puff pastry piece horizontally.
3. Lay the dough with the cuts facing down. Add hazelnut cream to the center of the dough, then fold it into a triangle.
4. Put them on a baking tray. Paint each puff pastry with milk and sprinkle with a little sugar. Bake for 25 minutes at 200°C (392°F).
5. Dust with icing sugar to serve.
